The evolution of integrated circuits has been toward increasingly smaller packages with an increasingly larger number of terminals for electrical interconnection between the integrated circuit and the circuit board on which it resides. As the number of terminals per integrated circuit has increased, the leads themselves have become finer and more closely spaced, thereby increasing the difficulty in mounting these fine lead integrated circuits to the circuit board.
One method of overcoming this difficulty is to replace the leads, which are typically located about the perimeter of the integrated circuit package, with contacts located on the bottom surface of the integrated circuit package to form a leadless integrated circuit package. These contacts are typically shaped as small protuberances or "balls" located in a grid array. The integrated circuit package having these surface contacts is then placed within a leadless integrated circuit socket or mounting device which holds the integrated circuit package in place. The mounting device has an array of electrical contacts which align with the ball contacts of the grid array on the integrated circuit package to provide electrical continuity between the circuit board upon which the mounting device is located and the integrated circuit package.
One problem that arises, not only with leadless but with leaded integrated circuit packages, is that the electrical contacts of the mounting device and the integrated circuit package become oxidized which results in increased contact resistance and therefore decreased conduction between the integrated circuit package contacts and the socket contacts. The act of inserting the leads of an integrated circuit package into a socket or the flux used in soldering the leads of the integrated circuit package to a circuit board typically removes at least some of this oxide, thereby providing a better electrical contact. However, since leadless integrated circuit packages are not inserted into a mounting device in a manner conductive to removal of the oxide on the contacts, and since leadless integrated circuit packages are not soldered to the mounting device, the accumulation of oxide on the contacts can result in a poor electrical connection.